Features

Ballmer pleasing its shareholders ..Screenshot from KMPlayer 0.9.1, controlpanel will shift upwhen moving the mouse near bottom of videoso you can peek in playlist for eg. bookmarking a specific URL

Highlights are

play movies from file/url using MPlayer, Xine (with *kxineplayer) or GStreamer (with *kgstplayer), making the plugin support as many as possible and, because all three are embedded external programs, keeping konqueror from crashing,

keep movie sizes ratio

volume slider using backend players' volume control and a volume slider using kmix or sound mixer applet (kicker) in the pop-down menu,

position slider

Javascript support for controlling the plugin from web page's javascript, and of course preventing script errors on pages calling these functions,

bookmark menu in the popup menu, so you can easily bookmark a stream for later w/o having to visit the web site all the time,

support for typical used playlist formats as ASX, RAM, m3u, pls, partially SMIL and multi-media links in podcast RSS or ATOM feeds and a dockable viewer for it. This allows you to easy navigate or bookmark certain streams.

The stand-alone player (libkdeinit_kmplayer.so) shares its core (libkmplayercommon.so) with the plugin's (libkmplayerpart.so) one, keeping both plugin and stand-alone player as lean (and secure) as possible. Actually, I wouldn't be suprised if the majority of KMPlayer users only use the plugin and use one of the other great movie players for KDE for other means.
The stand-alone application can additionally:

Lots of configurable shortcuts. Highly recommended for the VDR keys (if you have VDR) and volume increase/decrease.

Simple XML editor that make the XML under the current selected node editable and allows you to sync it back at that point in the tree

*backend players that come with KMPlayer. These players are simple command line applications (xsreensaver compatible) that embed inside KMPlayer. Communication is done using DCOP.

Help wanted

Some things simply stay low on my priority list, simply because I don't need it right now. Anyway, if you like to contribute to KMPlayer, have a look at this:

Fix the debian build, don't end with an error, make kmplayer package a real meta package of -lib, -plugin and -app.

Improve the GStreamer backend (kgstplayer), audio visualisations, dvdnav, flash, etc. Note, flash already works with the gstswfdec plugin. Unfortunately it performs not very well. Fixing this would allow kmplayer to replace the binary only flash plugin for konqueror.

MEncoder/FFMpeg encoding options.

A new name, KMPlayer sounds like a frontend to MPlayer, no?

Mute feature.

Improve the TV playback. Currently device scanning is done using MPlayer, but should be done more reliable (eg. HAL or XVideo). Channel scanning is nice of course. Maybe an extra backend, like tvtime.